[Wien] interband transition

[Peter Blaha]

>   I am using wien2k_09 for calculation of the optical properties of the
> perovskite oxide. Our calculated band structure composed of 29
> occupied band and 23 unoccupied (based on the convention of the Wien2k
>   we name the topmost band of the VB as No.29 and bottommost band of
> the CB as No.31).

??? I hope you mean 29 and 30 ??

> We  find  direct transitions from at and below  24th band to
> conduction bands  while we don’t see any transition from 25,26,…,29
> bands to conduction bands? How can I interpret it?

I do not believe this statement.
How do you come to these conclusions ???


> Also, I calculate the interband contributions (SWITCH 5 in line 4 of
> case.injoint), I obtain output files from case.Im_eps_xx_1 until
> case.Im_eps_xx_99  but I can't obtain more than 100 files (for example
> case.Im_eps_xx_100). I'd like to know how to obtain it ?

I'm not sure if switch 5 is really useful for more complicated cases, as 
the number of combinations grows very fast ....

In many cases a lable "band 26" is even meaningless, since the 26th 
eigenvalue at each k-point may originate from a different character, 
irrep,...., thus it basically does not ell you anything.

I prefer the analysis in "groups of bands", energy-regions AND character 
of the optical matrix elements.

For this, the first important point is to understand the electronic 
structure, i.e. understand at what energy region are which states (i.e 
where are the Zr-d states, where the O-p, ...) or deeper, what is "band 
26" ??? (i.e. it has Zr-4d-z2 character)

Then split your eps-2 calculations by a "clever" setting of energy 
ranges and band-indices setting in case.inop and case.injoint.

You should be able to decompose the total eps-2 into a couple of 
sub-spectra.

In addition you could "manipulate" the optical matrix elements by 
allowing only transitions from one particular atom (inop) and get the 
individual subspectra (but here you will miss crossterms, but still very 
often useful statements can be made).



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                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
Email: blaha at theochem.tuwien.ac.at    WWW: 
http://info.tuwien.ac.at/theochem/
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